Ok, guys, let's see it that way : we have one given element and we
want to find its 3rd element child. Very simple and common query,
right ?
1. using my proposal :
myFooElement.childElements.item(3);
2. using Selectors API :
myFooElement.querySelector("*:nth-child(3)") does NOT work since
there can be another 3rd child in traversal order before the
3rd child of myFooElement. I have no way of querying the 3rd child
of myFooElement alone if myFooElement has no ID, no class, nothing
since the :root pseudo-class does NOT apply to myFooElement in such
a query but still represents the root of the document.
Querying :first-child+*+* does not work either for the same reason,
there can be a 3rd child deep in the subtree being before the 3rd
child of myFooElement in traversal order of the document...
This is a limitation of the Selectors API I detected long ago.
Mentioned it a few times, too.
3. using XPath :
document.evaluate('*[3]', myFooElement, null,
XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
null).snapshotItem(3);
How much do you bet that if you show this to web designers, they'll
find solution (1) usable and will probably SCREAM LOUDLY at
(2) and (3) ?
</Daniel>
